MSS SP 70.98-Cast Iron Gate Valves-(1998)

MSS SP-70-1998

Cast Iron Gate Valves Flanged and Threaded Ends

Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180 (703) 281 -661 3

COPYRIGHT Manufacturers Standardization Society of the Valve and FittingsLicensed by Information Handling ServicesCOPYRIGHT Manufacturers Standardization Society of the Valve and Fittings Licensed by Information Handling Services

SP-70-ENGL L778 H 5770b40 050LOb8 bllO

MSS STANDARD PRACTICE SP-70

An MSS Standard Practice is intended as a basis for common practice by the manufacturer, the user, and the general public. The existence of an MSS Standard Practice does not in itself preclude the manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance is established only by reference in a code, specification, sales contract, or public law, as applicable.

Unless otherwise specifically noted in this MSS SP, any standard referred to herein is identified by the date of issue that was applicable to the referenced standard(s) at the date of issue of this MSS SP. See Annex C.

In this Standard Practice d notes, annexes, and figures are construed to be essential to the understanding ofthe message of the standard, and are considered part of the text unless noted as ‘supplemental.’ All footnotes appearing in this document are construed as ‘supplemental‘ where their information does not modify the text to which they refer.

U.S. customary units in this SP are the standard; the metric units are for reference only.

I Substantive changes in this 1998 edition are “flagged’’ by parallel bars as shown on the margins of this paragraph. The specific detail of the change may be determined by comparing the material flaged with that in the previous edition. I

Any part of this standmd may be quoted. Credit lines should read ‘Extracted porn MSS SP-70, 1998, with penniwwn of the publisher, the Manufacturers Standardization Society.’ Reproduction prohibited under copyright convention unless written permìwwn is granted by the Manufacturers Standardization Society of the Vahe and Fittings Inhtry, Inc.

OrigbUy Approved 1970

Copyright 8,1984 by Manufacturers Standardization Society

of the Valve and Fittings Industry, Inc.

printed in U.S.A.

i


STANDARD PRACTICE SP-70

FOREWORD

The 1998 edition of MSS SP-70, in addition to various editorial changes, includes changes to: provide a more complete metric version for reference use, delete the Class 800 Pressure-Temperature rating, and expand Annex C to include IS0 references.



CONTENTS

SECTION PAGE

FOREWORD ........................................................................ ii ... CONTENTS .......................................................................... m

1 . SCOPE .............................................................................. 1

2 . VALVE DESIGNATION. CLASSES AND SIZES ......................................... 1

3 . PRESSURE-TEMPERATURE RATINGS ................................................ 1

4 . MATERIALS ........................................................................ 1

5 . DESIGN ............................................................................. 2

6 . WORKMANSHIP .................................................................... 4

7 . TESTS .............................................................................. 4

8 . MARKING .......................................................................... 4

9 . PAINTING .......................................................................... 4

TABLE 1 . PRESSURE-TEMPERATURE RATINGS. NON-SHOCK-psi ........................ 2 TABLE 2 . HYDROSTATIC OR GAS SHELL TEST PRESSURE ............................... 4 TABLE 3 . DURATION OF TESTS ...... , ..................................................... 4 TABLE B1 . PRESSURE-TEMPERATURE RATINGS, NON-SHOCK-bar ........................ 8

FIGURE 1 . RISING STEM. SOLDWEDGE GATE VALVE. TYPE I ........................ 5 2 - NON-RISING STEM. SOLDWEDGE GATE VALVE. TYPE I ................... 5 3 - RISING STEM. SPLIT-WEDGE GATE VALVE. TYPE II ........................ 6 4 - NON-RISING STEM. SPLITWEDGE GATE VALVE. TYPE II ................... 6 5 - RISING STEM. DOUBLE-DISC. PARALLEL SEAT GATE VALVE. TYPE III ..... 7 6 - NON-RISING STEM. D0UBLE.DISC. PARALLEL SEAT GATE VALVE.

TYPE III ................................................................... 7



SCOPE 1. -

I . 1 This standard practice covers cast iron gate valves with flanged or threaded ends.

1.2 These valves are suitable within the sizes and pressure-temperature ratings specified herein for general purpose service.

1.3 This standard practice also includes, directly or by reference, stipulations on chemical and physical properties of materials, and dimensions of end connections in common use.

2. VALVE DESIGNATION, CLASSES AND SIZES

2.1 Valve Types. Valve types covered herein are illustrated in Figures A 1, A2, A3, A4, A5, and A6 in Annex A.

Type I-Solid Wedge Disc Type II-Split Wedge Disc Type Ill-Double Disc, Parallel Seat

Note: The valve sketches herein are for the purpose of illustration and nomenclature only. They are not intended to exclude any design meeting this Standard Practice.

2.2 Construction Designation NT-Non-Rising Stem, Threaded End -

NF-Non-Rising Stem, Flanged End OT-Outside Screw and Yoke, Threaded End OF-Outside Screw and Yoke, Flanged End

2.3 T- (a) All Bronze (b) All Iron (c) Bronze with Ferrous Stem I (d) Non-Metallic Seating [

2.4 Classes 125 250

I 2.5 sizes. (a) NPS 2-48 @N5&1200), flanged end (b) NPS 2-6 @N50-150), threaded end I

3. PRESSURE-TEMPERATURE RATINGS

4.

I

3.1 Pressure-temperature ratings for the various classes of valves are shown in Table 1. Metric units (bar) are shown in Table BI in Annex B. The ratings specified are for valves with metal-to-metal seating surfaces. Pressure-temperature ratings for valves with non-metallic seat materials must be limited to reflect the physical characteristics of these materials at each temperature, and may be lower but in no case higher than the values shown in Tables 1 and B 1.

3.2 The temperature shown for the corresponding rating shah be the metal temperature of the pressure retaining parts. It shall be assumed that the metal temperature will be the temperature of the contained fluid. Use of a pressure rating at a metal temperature other than that of the contained fluid shall be the responsibility of the user.

MATERIALS

4.1 General. This standard practice is intended to cover minimum physical and chemical requirements. Materials of superior mechanical properties may be substituted. Users are cautioned against applications with fluids which may react chemically with any materials used in these valves. Consultation with the manufacturer is advised to determine suitability in cases of doubt.

4.1.1 Body and Bonnet. Body and Bonnet shall be gray iron in accordance with ASTM A 126 Class B or ductile iron in accordance with ASTM A 536 or ASTM A 395. I 4.1.2 Seating Material. Metal-to-metal seating surfaces shall be brass or bronze for bronze mounted valves; cast iron or other ferrous material for all-iron valves. Other materials suitable for the intended service may be furnished when agreed between pur- chaser and manufacturer.

4.1.3 Stems. Stem material shall be brass or bronze, either cast or wrought for bronze mounted valves, wrought steel for all-iron valves.

4.1.4 Handwheels. Handwheels may be gray iron, ductile iron, malleable iron or steel at the manufacturer's option.



I TABLE 1 - PRESSURETEMPERATURE RATINGS, NON-SHWK-psi I CLASS 125 CLASS 250

Temp. 14-24 2-12 30-48 14-24 2-12 Degrees F. NPS NPS NPS NPS NPS

-20 to 150 300 500 150 150 200 200

270 440 100 130 180 225 , 280 460 115 135 190

250 275

260 415 85 125 175

220 335 100 150 350 230 355 105 155 325

250 395 65 120 1 70 300 240 375 50 110 165

375 200 290 140 400 210 315 145 I

425 250 125 450 270 130

*.

See Table BI for Metric U&.

4.1.5 Bo@ Bolts and studs connecting pressure contahîïïîïg-p "-3s shall develop physical strength not less than requirements-of ASTM A 307.

4.1.6 Glands, Glands shall be made from brass, bronze, gray iron or other ferrous material.

5. DESIGN

I 5.1 *c& When under the test pressure specified in Skct io~~ 7, valves shall be designed to prevent permanent distortion of the body, bonnet, or seats. I Valve stems shall be desiped to prevent permanent distortion when the valve is operated at full rated working pressure.

5'2 ip#&es shall be integral with the valve body. Dimensions, toleran& and drilling shall be in accordance with ASME B16.1 for each respective pressure class. The flanges shall be fully ,mchined on the joint side in accordance with MSS SP-6,

(b) Faceto-face dimensions of flanged end valves shall be as follows:

-dge

ASME B16.10 NPS 3 W ; * (DN750-1200)

NPS 2-24 (DN5G600)

Double Disc (Parallel Seat) Sizes 2-12; ASME B16.10 NPS 1418.* (DN350-450)

Class 250 (PN501 Solid or Split Wedge & Double Disc (Parellel Seat)

NPS 2-24 (DN50") ASME B16.10.

5.3 Threaded Ends. Threaded end bodies may have hexagon, octagon or round ends with ribs. Valve ends shall be threaded with tapered pipe threads in accordance with ASME B 1.20.1.

5.4 Body-Bo~et Bolting (a) Dimensions of bolts and cap screws shall be in accordance with ASME B18.2.1. Nut dimensions shall be in accordance with ASME B R 2 2

@) Nuts shall be threaded in accordance with ASME B1.1, Coarse thread series, Class 2B.

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SP-70-ENGL L778 5770bYO 0503073 T O B


(c) Bolts, studs or cap screws shall be threaded in accordance with ASME B1.1, Coarse thread series, Class 2A.

I 5.5 Yokes - Outside Screw and Yoke (OS & Y). Yokes on bonnets may be integral or of bolted-on construction. I 5.6 Wedge and Disc Guides and Disc Spreading

Device (a) Wedge discs shall be guided to ensure that the seating surfaces of the wedge will not touch the body seat surfaces until near the point of closure.

(b) Double discs shall be provided with guides or linkage or disc spreading devices between the gates or a combination of these which will hold the gates in proper relation with each other and the stem, and will prevent the seating surfaces from rubbing against the body or bonnet during operation.

(c) Body guides shall be cast integral with the body except that NPS 16 (DN400) and larger may have separate guides of bronze or other bearing material securely fasteded to the body. All guide surfaces shall be smooth and true.

I I (d) Selection of material for disc spreading devices shall be the manufacturer‘s option.

5.7 Seating Surfaces (a) Disc seating surfaces may be integral or may be separate rings securely fastened to the disc.

(b) Body seats shall be separate rings, either shoulder or bottom seated, except that all- iron valve seats may be integral with the body casting at the manufacturer’s option. Driving lugs may protrude into and reduce port area.

5.8 Glands (a) Glands may be threaded or bolted type.

(c) Stem seals not requiring a gland, but suitable for the service conditions, may be furnished.

5.9 Gland Bolting. Studs, stud bolts, hinge bolts or headed bolts through drilled or slotted holes in the stuffing box flange may be used. In all cases, gland bolting shall be securely held in place and shall provide adequate adjustment for progressive compression of packing material.

5.10 Backseat. Valves shall be designed to have a backseat. Repacking under pressure is hazardous and is not recommended.

5.11 Stems (a) The upper end of outside screw and yoke valve stems and the lower end of non-rising valve stems shall be threaded with single or multiple Acme type thread, or U e g r e e thread approximating the stub form, pre- cision cut to fit the engaging member.

(b) Outside screw and yoke stems shall be of sufficient length so as to be at least flush with the top of the yoke nut after the disc wedging has been worn into its lowest posi- tion. The design shall be such as to prevent any possibility of the wedge or disc leaving the stem, or the stem turning during the operation of the valve.

(c) Non-rising stem gate valves having separate stem engaging members shall be so designed as to prevent rotation or pulling out of the disc or wedge.

5.12 Handwheels. Handwheels shall be of the spoke type only. Webbed or disc type are not permissible. Handwheels shall be marked with the direction of movement for opening of the valve.

5.13 Bypass and Drain Connections. Unless otherwise specified, bypass and drain connections shall be in accordance with MSS SP-45.

(b) Bolted glands may be solid, solid-bushed, or two-pieced self aligning design. Use of open bolt slots in glands shall not be permitted unless hinge bolts are used.

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SP-70 STANDARD PRACTICE

6 YORKMANSHIP

6.1 General. Valve parts shall be designed and manufacturing tolerances set so as to provide inter- changeability in the product of any one manufacturer between units of the same size, class, type, and design, except the individual fit of the wedge or disc in the body.

6.2 Castin All castings shall be clean and sound without + efects which will impair their serviœ. No plugging, impregnation, welding or repairing of such defects will be allowed.

7. TESTS

7.1 Generala A shell test and a seat test shall be made on all completed valves prior to shipment by the manufacturer.

7.2 Shell Test. Valves in the partially open posi- tion with both ends closed.shall be subjected to hydrostatic or gas test pressure specified in Table 2. No visible leakage is permitted through the pressure boundary walls or body-bonnet joint. Leakage through the stem packing or stem seals shall not be cause for rejection. The test pressure shall be held for the duration specified in Table 3.

Caution: Safety precautions must be taken when gsisused.

I TABLE 2 - SHELL TEST PRESSURE, MINIMUM 1

Max. Serviœ Rating lSOF (6X) Test Pressure

Psi 10.3 150

bar Psi bru

36.2 525 20.7 300 24.1 350 13.8 #)o 18.3 265

60.3 c 5Qo 875 34.5

7.3 Hydrostatic Seat Test: Valves shall be subjected to a hydrostatic seit test at not less than the

maximum service pressure for which the valve is rated. Test pressure shall be applied successively on each side of the closed gate, and the opposite side checked for leakage. As an alternate method for double disc valves, the pressure may be applied inside the bonnet or body with the discs closed and both sides checked for leakage. The maximum permissible leakage rate on each seat shall be 10 milliliters per hour per inch of diameter of nominal valve size (.O7 mm3/sec x DN). Test pressures shall be held for periods specified in Table 3.

TABU 3 - TEST DURATION, SECONDS, MINIMUM I

t i

250-450 120

7.4 Gas Seat Test. At the manufacturer's option, a gas seat test of not less than 80 psi (5.5 bar) may be used in lieu of Hydrostatic Seat Test (7.3). The gas gressure is to be applied as specified for hydrostatic seat test. The maximum permissible leakage rate for each gate seat shall be 1 / 10 of a standard cubic foot of gas per hour, per inch of diameter of nominal valve size (2 mm3/sec x DN). Test pressures shall be held for periods specified in Table 3.

8.

9.

Caution: Safety precautions must be taken when gas is wed.

MARKING

Marking shall conform to MSS SP-25.

PAINTING

The painting of finished valves shall be optional with the manufacturer unless otherwise specified.

4


~

STD-MSS SP-70-ENGL L978 = 5770b40 0503075 880


ANNEX A VALVE TYPES

PART NAMES

2-Handwheel I-Handwheel nut

3--Stem nut 5--Stem nut bolts and nuts 6--Yoke 7-Stem 8“Glapd flange 9-Gland

IO-Yoke bolts and nuts I I - Gland bolts or gland eye-

bolts and nuts.

I 2-Gland lug bolts and nuts I3”Stem packing. or stem

18-Bonnet 19-Bonnet gasket 20-Bonnet bolts and nuts 21 Wedge 25 Seat ring 26-Body

seals

PART NAMES

I-Handwheel nut 2-Handwheel 3-Stem &Gland flange 5-Gland &Gland bolts and nuts 7-Stern packing. or stem

8-Stuffing box 9-Stuffing-box gasket

seals

IO-Stufiïng-box b o l t h and nuts or studs and nuts

I I-Bonnet gasket 12-Bonnet 13-Bonnet bolts and nuts I b B o d y IS-Upper wedge or wedge

I6”Seat ring 17-Wedge

bushing

RISING STEM, SOLID-WEDGE GATE VALVE

FIGURE Al

NON-RISING STEM, SOLID-WEDGE GATE VALVE

FIGURE A2 Note: The valve sketches herein are for the purpose of illustration and nomenclature only. They are not intended to exclude any design meeting this Standard Practice.

5


SP”ID-ENGL L778 5770bll0 050107b 717 m


ANNEX A VALVE TYPES

PART NAMES

I-Handwheel nut 12-Gland lug bolts and nuts 2-Handwheel 13-Stem packing, or stem 3-Stem nut ScalS 5-Stem nut bolts and nuts &Yoke

18-Bonnet 19-Bonnet gasket

7-Stem %Bonnet bolts and nuts &Gland flange 9-Cland

IO-Yoke bolts and nuls 2 6 w y 1 I - C l a n d bolts or gland eye-

21-Split d g e 25-Seat ring

-bolts and nuts

Type II

RISING STEM, SPLIT-WEDGE GATE VALVE

FIGURE A3

PART NAMES


3-Stem 4“Gland flange 5-Gland -land bolts and nuts 7-Stem packing, or stem

Il-Stuffing box 9-Stuffing-box gasket

seals

IO-Stuffing-box bolts and -nuts or studs and nuts

I I-Bonnet gasket 12-Bonnn 13-Bonnet b o l b and nuts 14-Body 15-Upper wedge or wedge

bushing If-Seat ring I7”Split wedge

Type I I

NON-RISING STEM, SPLIT-WEDGE GATE VALVE

FIGURE A4

purposc ofilustration and nomenclature only. Note: The valve sknche-s herein are for the

They are not intended to exclude any design M i n g this Standard Practice.

6



ANNEX A VALVE TYPES

PART NAMES


3-Stem nut 4-Stem nut retaining ring &Yoke 7-Stem B-Gland flange 9-Gland

IO-Yoke bolts and nuts I I-Gland bolts or gland eye-

bolts and nuts

Type III

I3”Stem packaking. or stem seals

I7”Stem back seat collar IB-Bonnet 19-bonnet gasket ”Bonnet bolts and nuts 2-Upper spreader 23-Disc 24”Lower spreader 25-Seat ring 2 f “ Y

PART NAMES


3-Stem &Gland flange 5-Gland 6”Gland bolts and nuts 7-Stem packing or stem

8”Stuffing box 9”Stuffing-box gasket

IO-Stuffing-box bolts and nuts or studs and nuts

sea$

I ILBonnet gasket 12LBonnet 13”Bonnet bolts and nuts 14-Body 15-Upper wedge or wedge

I G S e a t Ring 18”Upper spreader

20”Lower spreader I9”Disc

bushing

Type III

RISING STEM, DOUBLE-DISC PARALLEL SEAT GATE VALVE

FIGURE A5 Note: The valve sketches herein are for the purpose of illustrationand nomenclature only. They are not intended to exclude any design meeting this Standard Practice.

NON-RISING STEM, DOUBLE-DISC PARALLEL SEAT GATE VALVE

FIGURE A6

7



ANNEX B METRIC UNITS

I TABLE B1 - PRESSURE-TEMPERATURE RATINGS, NON-SHOCK-bar I

PN20 Temperature Degrees C. DN DN

50-300 350-600 -29 to 65

7.7 11.2 150 8.5 11.9 125 9.2 12.8 100

10.3 13.8

I75 10.4 7.0 200 9.6 205 225 8.8 232 8.6

PN50

DN 50-300 350-600 750-1200

DN DN

10.3 34.5 20.7 7.4 30.9 19.0 5.3 3.3

28.3 17.7 25.7 16.5 23.1 15.3 20.5 14.0

13.8 17.9 17.2

NOTE: For definitions of DN and PN, see International Standard IS0 6708 and IS0 7268, respectively, or MSS SP-86.

8


SP-70-ENGL 0503077 Y2b


I ANNEX C 1 REFERENCED STANDARDS

This annex is an integral part of this Standard Practice which is placed after the main text for convenience.

List of standards and specifications referenced in this Standard Practice show the year of approval.

ASME, ANSIIASME, ANSI, ASMEIANSI

B1.1-1989 Unified Inch Screw Threads (UN and UNR Thread Form) B1.20.1-1983 (R 1992) Pipe Threads, General Purpose (Inch) B16.1-1989 Cast Iron Pipe Flanges and Flanged Fittings (Class 25, 125,250, and 800) B16.10-1992 Famt*Faœ and End-to-End Dimensions of Valves B18.2.1-1996 Square and Hex Bolts and Screws, Including Askew Head Bolts, Hex Cap Screws, and Lag

Screws 818.2.2-1987 (R 1993) Square and Hex Nuts

ASTM - A 12695 Specifcation for Gray Iron Castings for Valves, Flanges, and Pipe Fittings

A 395-88 (R 1993) Specification for Ferritic Ductile Iron Pressure - Retaining Castings for Use at Elevated

A 53684 (R 1993) Specification for Ductile Iron Castings

A 307-94 Specification for Carbon Steel Bolts and Studs, 60,OOO psi Tensile Strength

Temperatures

SP-fk1990

SP-2S1998 SP45-1992 SP-861997

MSS

Standard Finishes for Contact Faces of Pipe Flanges and Connecting-End Flanges of Valves and Fittings Standard Marking System for Valves, Fittings, Flanges, and Unions Bypass and Drain Connection Standard Guidelines for Metric Data in Standards for Valves, Flanges, Fittings and Actuators

- IS0

6708-1995 Pipe Components - Definition of Nominal Pipe Size 7268-1983 (Amend 1, 1984) Pipe Components - Definition of Nominal Pressure

Publications of the following organizations appear on the above list:

ASME

ASTM

MSS

IS0

The American Society of Mechanical Engineers Three Park Avenue, New York, New York 100165990

American Society for Testing and Material 100 Bar Harbor Drive, West Conshohoken, Pennsylvania 19428-2959

Manufacturers Standardization Society of the Valve and Fitting Industry, Inc. 127 Park Street, N.E., Vienna, Virginia 22180

International Organization for Standardization 1, mede VarenBrd, Case postale 56, CH-1211 Geneve 20, Switzerland

Publications appearing above which have been approved as American National Standards may be obtained from:

ANSI American National Standards Institute, Inc. 11 West 42nd Street, New York, New York 10036

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MSS SP 70.98-Cast Iron Gate Valves-(1998)

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